Warp knitted fabric



1962 w. BOLTON 3,068,676

WARP KNITTED FABRIC Filed Feb. 7, 1958 3 Sheets-Sheet 1 w w w Off. :64p400 INVi/VTQR NIL-FRED BOLTON ATTMIVE) Dec. 18, 1962 w. BOLTON WARPKNITTED FABRIC Filed Feb. 7, 1958 3 Sheets-Sheet 2 V M/VE/VTOR WTLFREDBOLTON 6 A BY 1 0%. W ami ATTO Dec. 18, 1962 w. BOLTON WARP KNITTEDFABRIC 3 Sheets-Sheet 3 Filed Feb. 7, 1958 A TTo/a/ve Unite Stats PatentOhtice 3,068,676 Patented Dec. 18, 1962 This invention appertains towarp knitted fabrics, that is to say fabric comprising chains or walesof ordinarily meshed knitted loops which are formed from individualthreads or ends and are connected laterally.

Moreover, the invention is concerned with close warp knitted fabric,that is to say, fabric produced with a full set of threads, i.e. withone thread to each needle, and the loops are joined sideways at at leastevery alternate course. The invention is applicable not only to whollyclose warp knitted fabrics, but to portions of close warp knitted fabricincorporated in other types of fabric.

Broadly speaking, then, the invention is applicable principally to closefabrics such as those having plain laps, ribbed laps, knock-off laps andcrepe or knop laps, but also in suitable cases may be applied to openfabrics exemplified by pillar or chain nets, lace nets, gimped or inlaidnets and satin nets.

The primary object of the present invention is to provide, in warpknitted fabrics, novel patterning effects whereby a new range ofpleasing patterns and designs of practically infinite scope and varietycan be produced in a simple manner resulting also in unorthodox textureof the fabric.

Now faults caused in Warp knitted fabrics by normally undesiredinterference with, or interruption of, the controlled run-in of the warpends, during knitting, are very noticeable both on the back and the faceof the fabric, irrespective of the lapping movements of the threadguides employed. The effects of faulty warp knitting are all the morepronounced when yarn such as nylon is being knitted which yarn, besidesbeing immensely strong, is capable of considerable stretch and of fulland immediate recovery. Such faults, moreover, are very prominent whenwarp knitted fabrics, by virtue of being knitted with yarns of finedeniers have a tendency to transparency.

Thus, for instance, there is the fault caused by dragging thread andrevealed, in the case of a 1 x 1 lap tricot, as an apparent joining orrunning together of the two needle wales concerned in the making of thelaps; This appearance is due to the fact that loops in these particularneedle wales are formed with ends under a greater tension than the endsused in forming surrounding loops. All the needle loops in the area ofthe fault are affected, and the prominence of the fault depends, ofcourse, on the amount of tension to which the appropriate ends aresubjected during the dragging period. In any event, there is a markedcontrast between the tightened loops of a dragging thread fault and thesurrounding loops formed under normal conditions long before thebreaking point of the tensioned ends is reached.

A second fault is one caused by slackening of warp ends resulting insnarling of the slackened ends which latter bubble through the groundstructure.

As will be appreciated the faults referred to are normally rare owing tomodern warp knitting methods, good quality yarns and the efiicient useof skilled labour.

An aim of the present invention, however, is deliberately to cause suchfaults in a controlled manner, and in predetermined sequences, resultingin the aforementioned patterns and designs. In short, the invention isbased upon the judicious exploitation of known knitting faults.

The improved warp knitted fabric constituting this invention isaccordingly patterned by effects, hereinafter for convenience referredto as concentrations of tightened loops, produced by interference with,or interruption of, the controlled run-in of selected warp ends, duringknitting of the fabric.

According to a feature of the invention there is provided a warp knittedfabric which is patterned by desired dispositions of concentrations oftightened loops produced by reducing the normal rate of run-in of, andthereby tensioning or dragging, selected ends suchwise as to causeneedle wales to have the appearance of running together overpredetermined courses as hereinbefore described.

In accordance with another feature, there is provided a warp knittedfabric which is patterned by desired disposition of concentrations or"tightened loops produced by increasing the normal rate of run-in of, andthereby slackening, selected ends suchwise as to cause snarling of thoseends and bubbling of the latter through the ground structure.

Or, one and the same piece of Warp knitted fabric may incorporateconcentrations of tightened loops of the two kinds, viz. those producedboth by tensioning or dragging, and slackening of predetermined ends.

Considered from its broadest aspect, the overall method producing apatterned warp knitted fabric of the gen' erally improved charactertherefore consists in maintain ing, throughout their length, acalculated run-in of appropriate warp ends suchwise as to produce aground of standard (normal) structure, and interfering with, orinterrupting, the controlled run-in of each of selected ends during theknitting of predetermined courses so as to produce concentrations oftightened loops but permitting the selected ends to run-in normallyduring the knitting of the remaining courses of the fabric. Thus, in theintervening periods between the periods of its abnormal run-in eachselected end is allowed to resume its normal controlled run-in.

For producing concentrations of tightened loops of the dragging threadtype, the normal rate of run-in of said selected ends is reduced toapply tension to the latter, whereas to produce concentrations of thesecond type hereinbefore described the normal rate of run-in of selectedends is increased to slacken the same.

Broadly considered, the means provided in conjunction with a warp loomfor interfering with or interrupting the controlled run-in of selectedwarp ends may conveniently comprise, in combination, at least one row ofindividual and suitably guided warp end interfering members, one to eachof predetermined ends or groups of ends in a series of ends threadedthrough the guides of a guide bar, relatively stationary tensionelements adjacent to which the ends run, said elements being arranged atopposite sides of, and adapted to co-operate with, the interferingmembers, selectively operable actuating members each connected with someof the interfering members and adapted, when moved selectively in onesense, to raise or lower selected interfering members and so cause themto engage and lift or lower portions of the corresponding ends or groupsof ends extending between the tension elements but when moved in thereverse sense to respectively lower or raise the elevated or loweredmembers and so return the relevant ends or groups of ends to theirnormal path and patterning mechanism for controlling the ac tuatingmembers.

Conveniently, the warp end interfering, i.e. lifting or lowering membersmay be vertically movablein which instance the actuating members mayconsist of horizontally shiftable rods or the like which are connectedwith the interfering members by flexible elements passing over groovedpulleys or equivalent. In any event, warp end 3 interfering members ofthe row are each adapted to engage a group of, say, two, three or fourselected ends.

In order that the invention may be more clearly understood and readilycarried into practical effect, specific examples of warp knitted fabricsproduced on a two bar warp loom and patterned by concentrations oftightened loops, will now be described with reference to theaccompanying drawings, wherein,

FIGURE 1 illustrates, on a greatly magnified scale, the back of aportion of plain, single bar 1 X 1 warp knitted fabric incorporating aconcentration of tightened loops produced by tensioning or draggingselected ends,

FIGURE 2 depicts, on a much smaller scale and for purpose of comparison,adjoining portions of single bar and double bar fabric both patterned byconcentrations of tightened loops produced by dragging selected pairsmoreover, has normally straight prominent wales W and the crossings ofthe warp ends resulting from the manner of lapping are indicated at c.The two adjoining wales W and W5 are involved in the concentration oftightened loops fs these wales, as a consequence of a single warp endbeing lifted and tensioned, having the appearance of ends inpredetermined wales and over desired courses, 1

FIG. 3 is a diagrammatic representation of a portion of tricot fabrichaving double or plated knitted loops and showing a concentration ofloops involving two wales which are distorted towards one another andproduced by tensioning or dragging a single warp thread or end,

FiZGURE 4 illustrates a portion of 1 X 1 tricot combining concentrationsof tightened loops produced in accordance with this invention withconventional patterning, as will be hereinafter described.

The portion of plain 1 x 1 fabric F shown in FIGURE 1 is produced on thesingle set of needles of a double bar loom co-operating with the frontbar only of the latter. As, will be seen, the illustrated portion offabric F incorporates a concentration of tightened loops is whichinvolves three adjoining wales W W2, and W3 and is produced by liftingand thereby tensioning or dragging two adjacent warp ends. The normalrate of run-in of these two ends is, therefore, reduced and the resultis to drag and bunch knitted loops together into a knot adjacent towhich small. openings 0 occur. FIGURE 1 accordingly depicts a typicalconcentration of tightened loops produced by dragging Warp ends anddistorting loops in a single bar fabric.

In FIGURE 2 a much more extensive portion of such single-bar fabric isindicatedat F, this portion being patterned by predetermineddispositions and sequences of concentrations of tightened loops fs ofthe character described in the last preceding paragraph, and beingadjoined by a .portion of two-bar fabric F patterned by other sequencesof more tightly formed concentrations of tightened loops fs Thus, inmaking. the portion of two-bar fabric F the back guide barris only halfset, i.e. with warp ends threaded through alternate ones only of thethread guides of the said bar, the latter being shogged suchwise as toproduce 2 x l lapping. The front bar, on the other hand, is fully set orall in, i.e. with warp ends threaded through all of the guides in thebar and the latter is actuated to produce 1 x1 tricot lapping. Of theseries of warp ends threaded through the front guide bar alternate pairsof these ends are permitted to run-in normally, whilst the interveningpairs are lifted to produce the desired sequences of concentrations oftightened loops fs by the dragging thread technique. Although forconvenience of illustration in FIGURE 2 a portion of single bar fabricis shown actually adjoined to a portion of double-bar fabric it wouldusually be the intention (without limitation in this respect) to producesuch fabrics separately.

FIGURE 3 illustrates the incorporation of a concentration of tightenedloops is in a true singletricot fabric F that is to say double 1 1 warpknitted fabric made on one set of needles'co-operating with two fullyset guide bars each making similar laps but in opposite directions. onesin plated relation. Thus, it will be realised that the un-shaded knittedloops l at the back of the fabric of joining or running together at d.In practice, the tightened and distorted knitted loops in the area dcontrast markedly with surrounding normal loops.

Front bar loops such as l which, due to their positions on the needlestems when lapping, normally plate on the face of the fabric as shown inFIGURE 3 tend to be distorted at the times when concentrations oftightened loops such as fs are being formed. No such disturbance is, infact, shown in FIGURE 3 as it may not always and does not inevitablyoccur. But where conditions are such that disturbance of the platingrelationship of face ioops l with respect to loops 1 of the back Warpends is likely to occur then the relative displacement of the front andback loops may be relied on to produce two-tone efiects when usingcontrastingly coloured front and back warp ends. But to ensure that thedisturbed plating is uniform throughout the width of the fabric,appropriate adjustment of the needle bar and other machine settings maybe required.

In the warp fabric illustrated in FIGURE 4 a ground structure orbackground F of l X 1 tricot produced by the co-operation of two fullyset guide bars with a single set of needles, is ornamented by thecombination of conventional patterning f with concentrations oftightened loops rfs produced in accordance with this invention. Thepatterning f in this case consists of horizontal stripes produced byvarying the lapping of the front guide bar: thus, throughout the coursesover which each of the stripes extends the laps on the front bar arechanged from 1 X l to 2 X l or even 3 X 1. Alternate pairs of the warpends extending through the said front bar are liftable selectively totension or drag these ends andso produce the concentrations of tightenedloops fs instead of being in the form of stripes, however, theconventional patterning may consist of diamonds, squares or any otherappropriate geometrical designs.

Each concentration of tightened loops can extend, walewise, over anyappropriate number of courses and although the invention is by no meanslimited in this regard it may be mentioned that concentrations extendingover anything from, say, eight to twelve or more courses are usuallysufficiently bold for the purpose in view. As will be realised,moreover, concentrations of tightened loops can be produced inpredetermined wales and over any desired courses--either in selectedareas, or throughout the full width of the fabric. Accordingly, thepatterning scope is almost unlimited and practically infinitelyvariable. For example, the concentrations of tightened loops may be sodisposed in the improved fabric as to provide floral type designs,all-over effects, mock intarsia patterns, and various geometricaldesigns including those based on vertical or/ and horizontal stripesor/and blocks, diamonds and the like. Designs such as are adopted inlace and embroidery work can also be freely used. a

The number of initially separate warp ends incorporated in eachconcentration of tightened loops may also vary in which regard thelapping movements imparted to the ends during the knitting of the fabricare an important factor contributing to the ultimate results. It is,

' however, found that to be of a bold and outstanding tip In such fabricthe knitted loops are double lie behind and are hidden by the shadedknitted loops pearance a concentration should normally be at least twoneedle wales in width. For instance, in a 1 X 1 lap tricot groundstructure, and notwithstanding what is shown in FIGURE 3, concentrationsof tightened loops each involving three needle wales are considered tobe most satisfactory, and such effects may conveniently be produced byadopting a warp end set-out wherein spaced pairs of ends are selected tohave their controlled run-in interfered with or interrupted whileintervening pairs of ends are permitted to run-in normally.Theoretically, of course, the larger the number of ends used inproducing the concentration of tightened loops, the greater will be thecontrast between these concentrations and surrounding loops, but, inpractice, and to provide for maximum patterning scope, it is found thatselected ends interfered with or int rrupted in pairs, or in smallgroups of three or tour, will satisfactorily cover most effects andlapping systems.

it is to be noted, moreover, that when producing concentrations oftightened loops by deliberate and judicious tensioning or dragging ofselected ends, recovery of normal run-in of the said ends, aftercontrolled reduction of the normal rate of such run-in, tends to formslack loops which are visible on the face and back of the fabric. Slackloops formed in this way are not, however, detrimental and in someinstances may enhance the design by virtue of producing shadow effect. 7

The depth, i.e. the walewise extent, of a complete pattern or designconstituting dispositions of concentrations of tightened loops as hereindefined, may also vary widely according to requirements.

I claim:

1. A close Warp-knitted fabric comprising a plurality of warp endsknitted into wales of generally uniformly knitted loops, said walesbeing interconnected by weftwise-extending lapped portions of said Warpends, said fabric having at each of predetermined points therein aconcentration of tightened and distorted selected ones of said knittedloops, said concentrations of loops constituting patterningconfigurations contrasting with the uniform non-tightened andnon-distorted knitted loops.

2. A close warp-knitted fabric as claimed in claim 1,

wherein each of the said concentrations of knitted loops is in the formof a knop of said loops which are smaller and tighter than adjacentnormal knitted loops.

3. A double 1 x 1 close warp knitted fabric comprising front and backsets of similarly but oppositely lapped Warp ends knitted into wales ofgenerally uniformly knitted double loops in plated relation, said fabrichaving at each of pro-determined points therein a concentration oftightened and distorted ones of said knitted loops in two adjacentwales, whereby said wales have the appearance of running or joiningtogether over a plurality of courses, other ones of said knitted loopsbeing slack loops forming openings adjacent to each of saidconcentrations of loops.

4. A close warp knitted fabric as claimed in claim 3 wherein each ofsaid concentrations of loops is at least two wales in width and extendsover at least eight successive courses.

References Cited in the file of this patent UNITED STATES PATENTS1,201,803 Chace Oct. 17, 1916 1,482,705 Serra Feb. 5, 1924 2,015,818Schonfeld Oct. 1, 1935 2,030,459 Meinig Feb. 11, 1936 2,190,560 GainesFeb. 13, 1940 2,249,342 A1111 July 15, 1941 2,263,787 Safierson Nov. 25,1941 2,289,302 Bradshaw July 7, 1942 2,396,525 Newman Mar. 12, 19462,476,153 Little et a1. July 12, 1949 2,531,718 Rice Nov. 28, 19502,608,079 Slater Aug-26, 1952 2,718,132 Herrnstadt Sept. 20, 1955

